For information on the tsunami and how to pray and help, you can take a look at Tall Skinny Kiwi's post here.
Also, Kevin, at HippieChristian, recommends the following two Christian organizations:
Gospel for Asia
1800 Golden Trail Court
Carrollton TX 75010
(800) 946-2742 | (972) 300-7777
17011 W. Hickory
Spring Lake, MI 49456-9712
(616) 846-7490 | (800) 968-7490
Kevin has more links here.